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2 processes Task Manager
Google is your friend.
www.google.com Just use a specific search criterion. Farhan wrote: I am seeing two process in process explorer: 1- interrupts - hardware interrupts 2- DPCs - Deferred Procedure Calls They both take CPU very often. What are they? -- Farhan |
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#2
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2 processes Task Manager
Farhan wrote:
I am seeing two process in process explorer: 1- interrupts - hardware interrupts 2- DPCs - Deferred Procedure Calls They both take CPU very often. What are they? An interrupt is a signal the hardware sends to the CPU, when it needs the CPU's attention. The CPU runs an "interrupt handler", to take care of the needs of the hardware that raised the interrupt. Some events are asynchronous, such as when a packet is received on your Ethernet interface. When the packet arrives, the CPU needs to be told. An interrupt is a good way to do that. The interrupt, as the name implies, causes the processor to stop doing what it is currently doing, and pay attention to the hardware needing service. Once the interrupt handler is finished, the CPU returns to the application it was working on. The DPC is described here. http://en.wikipedia.org/wiki/Deferred_Procedure_Call The use of DPC, allows hardware servicing to be split into two pieces. The Interrupt Handler portion can have a short runtime, and only the most critical things are done there. Less critical things are scheduled for later execution, and that is where the DPC comes in. The DPC concept has been around for a while, and I think a software person in my group, described it to me somewhere around 1985 or so. If the entire handler ran at interrupt level, it would make the OS less responsive. Paul |
#3
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2 processes Task Manager
I am seeing two process in process explorer:
1- interrupts - hardware interrupts 2- DPCs - Deferred Procedure Calls They both take CPU very often. What are they? -- Farhan |
#4
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2 processes Task Manager
Paul wrote:
Farhan wrote: I am seeing two process in process explorer: 1- interrupts - hardware interrupts 2- DPCs - Deferred Procedure Calls They both take CPU very often. What are they? An interrupt is a signal the hardware sends to the CPU, when it needs the CPU's attention. The CPU runs an "interrupt handler", to take care of the needs of the hardware that raised the interrupt. Some events are asynchronous, such as when a packet is received on your Ethernet interface. When the packet arrives, the CPU needs to be told. An interrupt is a good way to do that. The interrupt, as the name implies, causes the processor to stop doing what it is currently doing, and pay attention to the hardware needing service. Once the interrupt handler is finished, the CPU returns to the application it was working on. The DPC is described here. http://en.wikipedia.org/wiki/Deferred_Procedure_Call The use of DPC, allows hardware servicing to be split into two pieces. The Interrupt Handler portion can have a short runtime, and only the most critical things are done there. Less critical things are scheduled for later execution, and that is where the DPC comes in. The DPC concept has been around for a while, and I think a software person in my group, described it to me somewhere around 1985 or so. If the entire handler ran at interrupt level, it would make the OS less responsive. Paul There is an example here, of someone with high interrupt/DPC, and it was related to UAA/HDaudbus.sys. http://forum.sysinternals.com/forum_...2982&PID=59372 Paul |
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